Safety contact-interrupter for suspended electric wires or cables.



' No.. 637,096. Patented Nov. 14,' i899.

y R. DUCORNOT.

l SAFETY CONTACT INTERRUPTER FCR SUSPENDED ELECTRIC WIRES 0R CABLES.

(Application tiled Mar. 11, 1899-) (No Model.)

S 21 Q l En y Q.

i FIGLI FIGr 'FIG Ji- @JQ @WL/ @@M UNITED STATES PATinwrV OFFICE.

RGER DUCORNOT, OF PUTEAUX, FRANCE.

SAFETY CONTACT-INTERRUPIER FOR SUSPENDED ELECTRlC WIRES QR CABLES.I y

SPECIFICATION forming part of Letters Patent No. 637,096, dated November 14, 1899.

. Application filed March 11, 1899.

.To @ZZ whom it may concern:

Beit known that I, ROGER DUcoRNoT, enf gineer, of Puteaux, Seine, in the Republic of France, have invented certain new and useful Improvements in Safety Contact-Interrupters for Suspended Electric Wires or Oables, of which the following is a full, clear, and exact description, reference lbeing had to the accompanying drawings,` forming part thereof.

' This invention relates to a contact-interrupter for suspended electric wires for safety purposes; and it consists of an apparatus of simple and operative construction which is arranged on the wires or cables of electric lines and'automatically'breaks the circuit as" soon as there is a breaking of these cables or wires, and thus prevents without fail the terrible accidents which often take place when an overhead wire or cable at high tension breaks, and suppresses generally all danger of tire incase of rupture of electric wires on lines Where it has been arranged.

,This apparatus or interrupter is essentially composed of a tube of insulating material closed at its two ends by two metal stoppers solidly joined to it. This insulating-tube is filled with mercury and oil. In order to fix the interrupter in place, the cable is cut and the extremities of the same, at which points the insulating-coverin g is removed, are united to the corresponding metal stoppers of the apparatus, care being taken to insure a perfect contact.

For a line worked with wires arranged on poles the interrupters, one of which is arranged, respectively, on each side of the pole, are arranged as near as possiblehorizontally in such a manner that in each of them the mercury extends along the length of the insulatingtube from one metallic stopper to another, while the oil oats upon the same and enables the currentto pass. If the cable breaks, the two pieces of the broken wire carried by neighboring posts fall to the earth; but, the interrupter becoming vertical or nearly vertical, the mercury iiows to the lower end of the tube, and the button at the upper end of the tube is in contact only with the oil lioating on the mercury. The current, which cannot pass through the oil, is arrest- Serial No. 708,672. (No model.)V

ed, and no sparks can be formed between the two ends of the cable nor any earth communication established between the broken ends. Any accident caused by the current is thus prevented, and after switching off the current the line can be mended and the intera rupter can act as before.

The annexed drawings fully illustrate the invention.

Figure 1 is a partial longitudinal section of the interrupter arranged on an electric cable. Fig. 2 is an exterior view of Fig. l. Fig. 3 is an exterior View of the interrupter covered entirely with insulating fabric. Fig. 4 shows the employment of the interrupter in combination with a connecting-frame for cables of great length or weight. Fig. 5 is a section of a variety of construction.

Referring to Fig. 1, the apparatus comprises, essentially, a tube a, ofinsulating nia-- terial-such as ebonite, porcelain, celluloid, or the likeand closed at each end by a metallic stopper, respectively, d and e, preferably of soft iron, which pass for a certain distance into thetube in the form of points or projections b and c of a smaller diameter than the interior of the tube. The stoppers are preferably screwed into the ends of the tube a, atight joint being effected by rubber washers Z, interposed between two leather washers. The joint is outwardly surrounded by an insulating-coverin g n, upon which galvanized or the like wire is strongly bound in the `form of a coil m.

Each stopper is providedwith an axial bore on its outer end, into which the bare end f of the cable is inserted. The bores are of such diameter that the cable ends do not quite fill them. The same are secured in the holes by pouring solder into the bores through and by means of a small hole s, provided for the purpose in the stopper, which insures a perfect contact. Set-screws U assist in maintaining the cable ends strongly in place. In the tube a, of insulating material, the neces sary quantities of oil h and mercury j are inserted.

The points or projections b and c of the stoppers inside the tube are preferably of unequal length, the shorter of the two, b, being always placed on the side of the pole in such IOO a manner that at a breaking of the cable the mercury comes entirely in the annular space around the longer point c, and the interval between the two points is occupied by the oil floating on the mercury.

The apparatus, being fitted up in position, is entirely covered with an insulating fabric t, which is fixed and made to agree at its extremities with the insulating-covering 7o of the cable, Fig. 3.

In the case of great lengths or weighty cables a frame in two longitudinal parts p q is used, which surrounds the tube and which grasps the cable with its two ends formed for the purpose. The respective ends of the frame-halves which grasp the cable are exteriorly conically formed and screw-threaded and are firmly pressed together and upon the cable by means of screw-nuts Fig. 4. The frame is constructed, preferably, of iron covered with ebonite; also, in order to reduce the quantity of mercury employed the body of the tube 0L can be thicker and of very short length, as shown in Fig. 5, and the points of the Stoppers can be dispensed with. The function of the apparatus would be the same. Finally in the case of employing theapparatus in cables in the open countrya thin layer of petroleum or other inliaminable product can be placed on the oil, so that when the cable breaks the petrolelim ignites and bursts the interrupter, the tube a of which is in this case made of thin Celluloid. The part of the cable between the fracture and the apparatus becomes thus detached and falls to the ground, allowing of the repairing of the line.

In any case it is necessary for complete security to have four interrupters per polethat is to say, two on each cable len gth-placed at about fifty centimeters from the poles.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. A contact-interrupter for suspended electric Wires breaking the circuit as soon 'as there is a breaking of the cable, with a thin celluloid tube or casing closed 'at each end by metallic Stoppers to which are united the two ends of the electric wire or cable, the said tube containing mercury, oil and a small quantity of petroleum, substantially as and for the purpose hereinbefore set forth.

2. A contactinterrupter for suspended electric wires breaking the circuit as soon as there is a breaking of the cable, with a tube or casing of insulating material filled with mercury and oil, closed at each end by metallic Stoppers extending for a certain distance into the tube in the form of points or projections b and c of unequal length, each stopper being provided with an axial bore on its outer end into which the bare ends of the cable are inserted, substantially as and for the purpose hereinbefore set forth.

3. A contact-interrupter for suspended elec* tric wires breaking the circuit as soon as there is a breaking of the cable, with a tube or casing a of insulating material filled with mercury and oil, closed at each end respectively by metallic stoppers d and e to which are united the two ends of the electric wire or cable, in combination with a metallic frame in two parts p q which longitudinally surround the tube 0r casing a and solidly con nect the two ends of the cable, substantially as and for the purpose hereinbefore set forth.

In witness whereof I have hereunto signed my name, this 28th day of February, 1899, in the presence of two subscribing Witnesses.

ROGER DUCORNOT.

Witnesses:

ANTOINE LAVoIX, EDWARD P. MACLEAN. 

